Chest CT Angiography for Acute Aortic Pathologic Conditions: Pearls and Pitfalls

Preoperative Imaging of the Thoracic Aorta

This article offers a comprehensive overview of the thoracic aortic anatomy and its pathologies, with a focus on the radiologic perspective. It begins with normal anatomy and imaging techniques, explores age-related changes and atherosclerosis, examines acute aortic syndrome and its various imaging presentations, and concludes with a review of thoracic aortic aneurysms and aortitis. Each section addresses the epidemiology, imaging characteristics, and briefly outlines treatment options.

Imaging and Surveillance of Chronic Aortic Dissection: Current Practice and Future Directions

Chronic aortic dissection is a complex disease with a heterogenous clinical course. Specialised imaging is necessary for the long-term surveillance of this disease to identify patients who meet the criteria for intervention, and to monitor surgically treated patients for complications. Whilst computed tomography and magnetic resonance imaging are the most widely utilised modalities, providing a high degree of anatomical detail and reproducible aortic measurements, they are not without significant limitations. These techniques cannot accurately predict patients that are at risk of late complications who may benefit from early intervention. Emerging techniques such as four-dimensional magnetic resonance imaging and computational fluid dynamics have identified multiple haemodynamic variables with potential prognostic value for identifying adverse events such as rupture, malperfusion, or aneurysmal degeneration, and may in the future become integrated into routine clinical practice. This review provides a detailed analysis of current diagnostic and surveillance imaging modalities in chronic aortic dissection and discusses future paradigms in aortic imaging to enable better prognostication and earlier intervention for high-risk patients.

Computed Tomography Imaging of Thoracic Aortic Surgery: Distinguishing Life-Saving Repairs from Life-Threatening Complications

Thoracic aortic pathology encompasses a spectrum of life-threatening conditions that demand prompt diagnosis and intervention. Significant advancements in surgical management, including open repair, endovascular aortic repair, and hybrid techniques, have markedly enhanced patient outcomes. However, these procedures necessitate meticulous imaging follow-up to identify potential complications. Computed tomography angiography remains the gold standard for evaluating aortic pathology, guiding surgical planning, and monitoring postoperative changes. A thorough understanding of the characteristic imaging features associated with various aortic surgical techniques is crucial for precise assessment, enhancing postoperative surveillance, and optimizing patient management. Distinguishing between surgical complications and postoperative findings is vital to prevent misdiagnosis. This review examines the imaging characteristics of thoracic aortic diseases and their corresponding surgical interventions, emphasizing the differentiation between expected postoperative findings and true pathological conditions. This approach aims to facilitate accurate diagnosis and effective management of complications, ultimately improving patient care.

CT angiography of acute aortic syndrome in patients with chronic kidney disease

The term acute aortic syndrome (AAS) refers to a range of different entities, including dissection, intramural haematoma and penetrating atherosclerotic ulcer. Patients with chronic renal disease and particularly those with dominant polycystic kidney disease are susceptible to this pathology, given the underlying renal arteriopathy and hypertension. Imaging plays a crucial role in diagnosing, grading and guiding management of these patients, with computed tomography angiography (CTA) being on the frontline. Albeit of overlapping of imaging findings between these conditions, specific imaging characteristics help discriminate and guide treatment. Given the nephrotoxic contrast agent involved, tailored CTA protocols or alternative imaging modalities such as MRI or US are necessary in this patient population. This review article discusses the main imaging findings of entities found in the spectrum of AAS, as well as the appropriate use and protocol of imaging modalities, focusing on the appropriate use of nephrotoxic contrast agents, the preservation of renal function and maintenance of optimal diagnostic accuracy.

CT diagnosis and destiny of acute aortic intramural hematoma

Acute aortic intramural hematoma (IMH) is a relatively uncommon but potentially life-threatening aortic disease that can occur primarily in hypertensive and atherosclerotic patients. The course of IMH varies widely, with the condition either regressing, remaining stable, or progressing until it leads to outward rupture or intimal layer disruption, eventually resulting in overt aortic dissection. Therefore, poor prognostic computed tomography (CT) features must be promptly recognized and reported by the radiologist. In emergency departments, readily accessible non-invasive CT angiography is crucial for achieving a rapid and accurate diagnosis essential for appropriate management. For Type A and B aortic dissection, surgery is typically recommended in Western countries for patients with Stanford Type A IMH and those experiencing irrepressible pain. For Stanford Type B IMH patients without complications or incessant pain, medical treatment is suggested but with imaging follow-up. In complicated Stanford Type B situations, thoracic endovascular aortic repair (TEVAR) is currently indicated. This review aims to present pathophysiology, CT diagnosis, and IMH fate and provide the reader CT image-based review of the CT diagnostic criteria, complications, and associated critical prognostic findings of this rather rare aortic disease.

Short segment linear "flaps" of the abdominal aorta: proposed mechanism of origin and evaluation of natural history via retrospective imaging review

PURPOSE

Luminal linear findings (LLF) of the abdominal aorta are often called aortic "flaps," triggering concern for acute aortic syndrome. However, these "flaps" are unlikely to represent intimomedial dissection given isolation to the abdominal aorta, short length, and incidental discovery. We aim to characterize the etiology and stability of LLF.

METHODS

CT reports finalized January 2021-December 2022 were queried for terms "focal dissection," "dissection flap," "linear filling defect," and "linear flap." Patients were excluded for thoracoabdominal dissection, LLF in non-aortic vessel, no prior contrast-enhanced imaging, and less than 6 months between exams. Index exam reviewed for presence of LLF, atherosclerosis, and aortic caliber at LLF site. Prior exam assessed for aortic caliber and aortic findings at subsequent LLF site. Patients with unchanged LLF between exams were categorized "Stable" and patients with interval change "Dynamic."

RESULTS

Seven hundred and two cases identified. After exclusions, imaging from 70 patients reviewed; 1 excluded for no LLF. Stable Cohort of 39 patients had median follow-up 31 months (range 6-284 months). 87% of aortas were moderately/severely atherosclerotic (n = 16 moderate, n = 18 severe), while 69% were ectatic/aneurysmal (n = 27). Dynamic Cohort of 20 patients had median follow-up of 70 months (range 14-244 months). All were atherosclerotic and 80% were ectatic/aneurysmal compared to 25% ectatic/aneurysmal at prior imaging. Mural thrombus was present at the site of the future LLF in 17 of 20, thrombosed PAU in 1, and no focal findings in 2.

CONCLUSION

Short-segment LLFs within the abdominal aorta arise from prior mural thrombus and demonstrate long term stability. Clinically and radiographically indolent, LLFs should not be called dissection flaps.

A Narrative Review of Biomarkers and Imaging in the Diagnosis of Acute Aortic Syndrome

Acute aortic syndrome (AAS) encompasses a range of life-threatening conditions, including classical dissection, intramural hematoma, and penetrating aortic ulcer. Each of these conditions presents distinct clinical characteristics and carries the potential to progress to rupture. Because AAS can be asymptomatic or present with diverse symptoms, its diagnosis requires clinical evaluation, risk scoring, and biomarkers such as D-dimer (DD), C-reactive protein (CRP), homocysteine, natriuretic peptides (BNP), and imaging modalities like computed tomography (CT), magnetic resonance imaging (MRI), and echocardiography. While this review primarily focuses on widely used and clinically accessible biomarkers and imaging techniques, it also discusses alternative biomarkers proposed for diagnostic use. Although CT remains the gold standard for diagnosis, biomarkers facilitate rapid risk stratification, complementing imaging techniques. Emerging technologies, such as metabolomics, are reshaping diagnostic algorithms. Despite advances in diagnostic methods, challenges such as misdiagnosis and missed diagnoses persist. Ongoing research into novel biomarkers and innovative imaging techniques holds promise for improving diagnostic accuracy and patient outcomes.

Vascular abnormalities not to miss on routine chest CT: A pictorial review

There is a wide and ever-increasing range of imaging indications for thoracic computed tomography (CT). Identifying and appropriately triaging cardiovascular findings is often challenging, especially in non-gated or unenhanced studies. The authors provide a pictorial review of clinically relevant abnormalities of the main intrathoracic vessels (aorta, superior vena cava, pulmonary arteries and coronary arteries), for radiologists reporting non-gated enhanced or unenhanced CT of the thorax.

Radiologic Assessment of Acute Aortic Syndrome With Multiple Penetrating Atheromatous Ulcers: A Case Report

Acute aortic syndromes (AAS) include life-threatening conditions like penetrating atheromatous ulcer (PAU), which occurs when an atherosclerotic plaque erodes through the aortic wall. This can lead to complications such as intramural hematoma, pseudoaneurysm, or aortic rupture, especially in the ascending aorta. PAUs typically affect older males with atherosclerosis and are most commonly found in the lower descending thoracic aorta, with multiple PAUs being rare. This report highlights a case involving the incidental discovery of multiple PAUs and an associated ductus diverticulum, and it discusses their presentation and management. An 88-year-old male with a history of hypertension, diabetes, and pulmonary fibrosis presented with right-sided upper quadrant and chest pain radiating to the back. Initial imaging suggested progression of pulmonary fibrosis or an infection, but a subsequent CT angiogram revealed at least 12 focal outpouchings in the distal aortic arch and proximal descending thoracic aorta, compatible with PAUs. Additionally, a ductus diverticulum was identified. The patient was managed with high-dose statin therapy and scheduled for follow-up CTA in three months. This case highlights the incidental discovery of multiple PAUs and a ductus diverticulum, underscoring the rarity and complexity of PAU presentations. It emphasizes the importance of including PAU in the differential diagnosis for patients presenting with chest pain, especially when symptoms are atypical or overlap with other conditions. Early identification and management are crucial to prevent severe complications such as aortic dissection or rupture.

Dynamic contrast-enhanced MRA of the aorta using a Golden-angle RAdial Sparse Parallel (GRASP) sequence: comparison with conventional time-resolved cartesian MRA (TWIST)

PURPOSE

To compare the application of two contrast-enhanced time-resolved magnetic resonance angiography sequences on an aortic disease patient cohort: the conventional Cartesian-sampling-based, Time-resolved angiography With Interleaved Stochastic Trajectories (TWIST) sequence, and the radial-sampling-based Golden-angle RAdial Sparse Parallel (GRASP) sequence. TWIST is highly sensitive to patient movement, which can lead to blurring and reduced sharpness of vascular structures, particularly in dynamic regions like the aorta. Such motion artifacts can compromise diagnostic accuracy. Radial-sampling-based techniques are less sensitive to motion than cartesian sampling and are expected to improve the image quality in body parts subjected to motion.

METHODS

30 patients (60.9 ± 16.1y.o.) with various aortic diseases underwent a 1.5T magnetic resonance angiography examination. Assessment of image quality in the ascending aorta (AA), descending aorta (DA), and abdominal aorta (AbA) on a 4-point Likert scale (1 = excellent, 4 = non-diagnostic) as well as max. aortic diameters (Dmax) were performed. T-test and multilevel mixed-effect proportional-odds models were used for the image analysis.

RESULTS

GRASP offered superior depiction of vascular structures in terms of vascular contrast for qualitative analysis (TWIST, reader 1: 1.6 ± 0.5; reader 2: 1.9 ± 0.4; reader 3: 1.1 ± 0.4; GRASP, reader 1: 1.5 ± 0.5; reader 2: 1.4 ± 0.5; reader 3: 1.0 ± 0.2) and vessel sharpness for qualitative (TWIST, reader 1: 1.9 ± 0.6; reader 2: 1.6 ± 0.6; reader 3: 2.0 ± 0.3; GRASP, reader 1: 1.4 ± 0.6; reader 2: 1.2 ± 0.4; reader 3: 1.3 ± 0.6) and quantitative analysis (TWIST, AA = 0.12 ± 0.04, DA = 0.12 ± 0.03, AbA = 0.11 ± 0.03; GRASP, AA = 0.20 ± 0.05, DA = 0.22 ± 0.06, AbA=0.20 ± 0.05). Streaking artefacts of GRASP were more visible compared to TWIST (TWIST, reader 1: 2.2 ± 0.6; reader 2: 1.9 ± 0.3; reader 3: 2.0 ± 0.5; GRASP, reader 1: 2.6 ± 0.6; reader 2: 2.3 ± 0.5; reader 3: 2.8 ± 0.6). Aortic Dmax comparison among the sequence showed no clinical relevance.

CONCLUSION

GRASP outperformed TWIST in SNR, vessel sharpness, and reduction in image blurring; streaking artefacts were stronger with GRASP, but did not affect diagnostic image quality.

Trauma and 'Whole' Body Computed Tomography: Role, Protocols, Appropriateness, and Evidence to Support its Use and When

Imaging plays a crucial role in the immediate evaluation of the trauma patient, particularly using multi-detector computed tomography (CT), and especially in moderately to severely injured trauma patients. There are specific areas of relative consensus, while other aspects of whole-body computed tomography (WB-CT) use remain controversial and are subject to opinion/debate based on the current literature. Even a few hours of a delayed diagnosis may result in a detrimental outcome for the patient. One must utilize all the tools available to enhance the interpretation of images. It is also important to recognize imaging pitfalls and artifacts to avoid unnecessary intervention.

Outcome After Conservative and Endovascular Treatment of Stanford Type B Aortic Intramural Hematomas - A Single-Center Retrospective Study

OBJECTIVES

Aortic intramural hematoma (IMH) is a rare disease. Thus far, only limited data is available and the indications for conservative and endovascular treatment are not well defined. The aim of this study was to investigate clinical presentation, course, CT imaging features and outcome of patients with type B aortic IMHs.

METHODS

We included all patients with type B IMHs between 2012 and 2021 in this retrospective monocentric study. Clinical data, localization, thickness of IMHs and the presence of ulcer-like projections (ULPs) was evaluated before and after treatment.

RESULTS

Thirty five patients (20 females; 70.3 y ± 11 y) were identified. Almost all IMHs (n = 34) were spontaneous and symptomatic with back pain (n = 34). At the time of diagnosis, TEVAR was deemed indicated in 9 patients, 26 patients were treated primarily conservatively. During the follow-up, in another 16 patients TEVAR was deemed indicated. Endovascularly and conservatively treated patients both showed decrease in thickness after treatment. Patients without ULPs showed more often complete resolution of the IMH than patients with ULPs (endovascularly treated 90.9% (10/11) vs 71.4% (5/7); conservatively treated 71.4% (10/14) vs 33.3% (1/3); P = .207). Complications after TEVAR occurred in 32% and more frequently in patients treated primarily conservatively (37.5% vs 22.2%). No in-hospital mortality was observed during follow-up.

CONCLUSIONS

Prognosis of IMH seems favourable in both surgically as well as conservatively treated patients. However, it is essential to identify patients at high risk for complications under conservative treatment, who therefore should be treated by TEVAR. In our study, ULPs seem to be an adverse factor for remodeling.

Rapid Diagnosis of Acute Type A Aortic Dissection Through Multimodality Imaging

•TAAD is a rare and potentially fatal disease. •Aortic dissections have a wide range of common risk factors. •This condition can mistakenly present similar to other acute coronary syndromes. •Clinicians need clinical expertise and proper multimodality imaging for diagnosis. •Misdiagnosis of this condition can be dangerous and fatal to patients.

[Acute aortic syndrome]

Acute aortic syndrome embraces a group of heterogenous pathological entities involving the aortic wall with a common clinical profile. The current epidemiology, clinical presentation, diagnosis and treatment strategy are discussed in this review. Besides, the importance of multidisciplinary aortic teams, aortic centers and the implementation of an aortic code are emphasized.

Mathematical modeling and numerical simulation of arterial dissection based on a novel surgeon's view

This paper presents a mathematical model for arterial dissection based on a novel hypothesis proposed by a surgeon, Axel Haverich, see Haverich (Circulation 135(3):205-207, 2017. https://doi.org/10.1161/circulationaha.116.025407 ). In an attempt and based on clinical observations, he explained how three different arterial diseases, namely atherosclerosis, aneurysm and dissection have the same root in malfunctioning Vasa Vasorums (VVs) which are micro capillaries responsible for artery wall nourishment. The authors already proposed a mathematical framework for the modeling of atherosclerosis which is the thickening of the artery walls due to an inflammatory response to VVs dysfunction. A multiphysics model based on a phase-field approach coupled with mechanical deformation was proposed for this purpose. The kinematics of mechanical deformation was described using finite strain theory. The entire model is three-dimensional and fully based on a macroscopic continuum description. The objective here is to extend that model by incorporating a damage mechanism in order to capture the tearing (rupture) in the artery wall as a result of micro-injuries in VV. Unlike the existing damage-based model of the dissection in the literature, here the damage is driven by the internal bleeding (hematoma) rather than purely mechanical external loading. The numerical implementation is carried out using finite element method (FEM).

Postoperative imaging of thoracic aortic repairs

Imaging plays a crucial role in the postoperative monitoring of thoracic aortic repairs. With the development of multiple surgical techniques to repair the ascending aorta and aortic arch, it can be a daunting challenge for the radiologist to diagnose potential pathologies in this sea of various techniques, each with their own normal postoperative appearance and potential complications. In this paper, we will provide a comprehensive review of the postoperative imaging in the setting of thoracic aortic repairs, including the role of imaging, components of thoracic aortic repairs, the normal postoperative appearance, and potential complications.

Bib Sign in Proximal Descending Thoracic Aorta Rupture on CT Angiography: Presentation of a Paradigmatic Case

Thoracic aortic rupture may present with subtle clinical and CT-angiography findings. Recognition of the imaging features of early rupture is key for timely diagnosis and treatment. This report presents a new sign of incipient proximal thoracic aortic rupture on CT-angiography.

Changes of Serum D-Dimer, NT-proBNP, and Troponin I Levels in Patients with Acute Aortic Dissection and the Clinical Significance

Objective

To investigate the changes in blood D-dimer (D-D), high-sensitivity troponin I (hs-cTnI), and N-terminal B-type brain natriuretic peptide (NT-proBNP) levels in patients with acute aortic dissection (AAD) and its clinical significance.

Methods

Forty patients with AAD diagnosed in our hospital from January 2018 to December 2019 were selected as the observation group, and 40 patients with chest pain and non-AAD treated in our hospital during the same period were included in the control group. The patients were subdivided into a death group and a survival group as per the prognosis. The clinical symptoms and signs of the two groups of patients upon admission were observed, and the levels of D-D, hs-cTnI, and NT-proBNP were determined. The differences in clinical data, plasma D-D, hs-cTnI, and NT-proBNP levels between the two groups of patients were analyzed.

Results

The clinical data and physical signs were homogeneous between the two groups (P > 0.05), while a significant elevation in the level of hs-cTnI in the control group was observed 24 h after admission (P < 0.05). The observation group showed significantly higher levels of D-D, NT-proBNP, and hs-cTnI than the control group (P < 0.05). The prevalence and surgical cure rate of Stanford A in the survival group were significantly lower in contrast with the death group, with an obvious higher intervention cure rate in the survival group. Higher D-dimer and NT-proBNP levels were identified at 24 h after admission versus upon admission, and the death group had a greater increase of D-dimer and NT-proBNP levels.

Conclusion

Clinical symptoms and signs are insufficient to constitute a diagnosis of AAD, whereas the elevated expression levels of D-D, hs-cTnI, and NT-proBNP demonstrated great potential for the diagnosis and prognosis of AAD.

Aortic dissection in Indonesia male: 3 case report

Background

Aortic dissection (AD) is a life-threatening rare condition caused by a tear in the aortic wall which requires urgent surgery.

Case presentation

3 Indonesian males obtained a CT angiography (CTA) showing a picture of AD which was confirmed using the Stanford and De Bakey classification. The patient was successful in undergoing TEVAR and open-heart surgery which 2 patients survived and 1 patient died.

Discussion

The speed of handling in AD is the key to successful management of AD supported by an understanding of the signs and symptoms and results of thoracoabdominal CTA.

Conclusion

The ability to interpret CTA results and understand AD sign symptoms is very helpful in minimizing mortality.

Thoracic Endovascular Aortic Repair for Aberrant Subclavian Artery and Stanford Type B Aortic Intramural Hematoma

Objectives

To evaluate the in-hospital and later outcomes of thoracic endovascular aortic repair (TEVAR) for type B intramural hematoma (TBIMH) combined with an aberrant subclavian artery (aSCA).

Methods

In the period from January 2014 to December 2020, 12 patients diagnosed with TBIMH combined with aSCA and treated by TEVAR were enrolled in this retrospective cohort study, including 11 patients with the aberrant right subclavian artery (ARSA) and 1 with an aberrant left subclavian artery (ALSA). A handmade fenestrated stent-graft or chimney stent or hybrid repair was performed when the proximal landing zone was not enough.

Results

The mean age of all the patients was 59.2 ± 7.6 years, and 66.7% of patients were men. There were 4 patients with Kommerell's diverticulum (KD). The procedures in all 12 patients were technically successful. There was one case each of postoperative delirium, renal impairment, and type IV endoleak after TEVAR. During follow-up, 1 patient died of acute pancreatitis 7 months after TEVAR. The overall survival at 1, 3, and 5 years for the patients was 90.9, 90.9, and 90.9%, respectively. KD was excluded in 2 patients, and the handmade fenestrated stent-graft was applied in the other 2 patients to preserve the blood flow of the aSCA. No neurological complications developed and no progression of KD was observed during the follow-up.

Conclusion

Thoracic endovascular aortic repair for patients with aSCA and TBIMH is promising. When KD was combined, we could exclude KD or preserve the blood flow of aSCA with regular follow-up for the diverticulum according to the size of the KD.

MDCT Imaging of Non-Traumatic Thoracic Aortic Emergencies and Its Impact on Diagnosis and Management—A Reappraisal

Non-traumatic thoracic aorta emergencies are associated with significant morbidity and mortality. Diseases of the intimomedial layers (aortic dissection and variants) have been grouped under the common term of acute aortic syndrome because they are life-threatening conditions clinically indistinguishable on presentation. Patients with aortic dissection may present with a wide variety of symptoms secondary to the pattern of dissection and end organ malperfusion. Other conditions may be seen in patients with acute symptoms, including ruptured and unstable thoracic aortic aneurysm, iatrogenic or infective pseudoaneurysms, aortic fistula, acute aortic thrombus/occlusive disease, and vasculitis. Imaging plays a pivotal role in the patient’s management and care. In the emergency room, chest X-ray is the initial imaging test offering a screening evaluation for alternative common differential diagnoses and a preliminary assessment of the mediastinal dimensions. State-of-the-art multidetector computed tomography angiography (CTA) provides a widely available, rapid, replicable, noninvasive diagnostic imaging with sensitivity approaching 100%. It is an impressive tool in decision-making process with a deep impact on treatment including endovascular or open surgical or conservative treatment. Radiologists must be familiar with the spectrum of these entities to help triage patients appropriately and efficiently. Understanding the imaging findings and proper measurement techniques allow the radiologist to suggest the most appropriate next management step.

CT of the Difficult Acute Aortic Syndrome

Acute aortic syndrome (AAS) is classically attributed to three underlying pathologic conditions-aortic dissection (AD), intramural hematoma (IMH), and penetrating atherosclerotic ulcer (PAU). In the majority of cases, the basics of image interpretation are not difficult and have been extensively reviewed in the literature. In this article, the authors extend existing imaging overviews of AAS by highlighting additional factors related to the diagnosis, classification, and characterization of difficult AAS cases. It has been well documented that AAS is caused not only by an AD but by a spectrum of lesions that often have overlap in imaging features and are not clearly distinguishable. Specifically, phase of contrast enhancement, flow artifacts, and flapless AD equivalents can complicate diagnosis and are discussed. While the A/B dichotomy of the Stanford system is still used, the authors subsequently emphasize the Society for Vascular Surgery's new guidelines for the description of acute aortic pathologic conditions given the expanded use of endovascular techniques used in aortic repair. In the final section, atypical aortic rupture and pitfalls are described. As examples of pericardial and shared sheath rupture become more prevalent in the literature, it is important to recognize contrast material third-spacing and mediastinal blood as potential mimics. By understanding these factors related to difficult cases of AAS, the diagnostic radiologist will be able to accurately refine CT interpretation and thus provide information that is best suited to directing management. Online supplemental material is available for this article. ^©RSNA, 2021.

Learning from mistakes when reporting urgent and emergency vascular studies

The majority of out-of-hours cases relate to neurological, chest, and gastrointestinal pathologies with acute vascular cases being encountered less commonly. Trainees and exposure of non-vascular/interventional radiology (IR) consultants to angiographic imaging is often limited in working hours and this may lead to reporting on-call cases outside of normal daytime practice. In a recent local review, a number on-call vascular studies were found to contain a number of vascular-related discrepancies. Vascular reporting is a complex subspecialty, which comprises many clear diagnoses (large vessel occlusions, large vessel aneurysms, or dissections); however, also several subtle and complex abnormalities. These more subtle abnormalities, at times, require dedicated vascular specialist review to ensure subtle findings are communicated appropriately to the clinical team. The recent increased complexity of endovascular treatments and their complications has also provided further challenge for the non-specialist reporter. Similarly, improved imaging techniques have allowed for non-obvious but significant findings that may require urgent management, such as small aneurysms and dissection flaps. We will review a range of key vascular findings that demonstrate learning opportunities, particularly within the acute and on-call settings. These will include gastrointestinal haemorrhage, subtle aortic pathologies, head and neck vascular emergencies, small to mid-sized vessel injuries and imaging of post-procedural complications. Educational hints and tips will be provided to enable learning from mistakes encountered by trainees and non-vascular specialist radiologists in the on-call or urgent reporting settings, and these will be reviewed with reference to the literature.

Acute Aortic Syndrome Revisited: JACC State-of-the-Art Review

The purpose of this paper is to describe all available evidence on the distinctive features of a group of 4 life-threatening acute aortic pathologies gathered under the name of acute aortic syndrome (AAS). The epidemiology, diagnostic strategy, and management of these patients has been updated. The authors propose a new and simple diagnostic algorithm to support clinical decision making in cases of suspected AAS, thereby minimizing diagnostic delays, misdiagnoses, and unnecessary advanced imaging. AAS-related entities are reviewed, and a guideline to avoid imaging misinterpretation is provided. Centralization of patients with AAS in high-volume centers with high-volume surgeons is key to improving clinical outcomes. Thus, the role of multidisciplinary teams, an "aorta code" (streamlined emergent care pathway), and aortic centers in the management of these patients is boosted. A tailored patient treatment approach for each of these acute aortic entities is needed, and as such has been summarized. Finally, a set of prevention measures against AAS is discussed.

Thoracic Endovascular Aortic Repair for Retrograde Type A Aortic Intramural Hematoma

Objectives: To evaluate the effects of thoracic endovascular aortic repair (TEVAR) in descending aorta for retrograde type A aortic intramural hematoma (re-TAIMH).

Methods: From January 2013 to September 2019, 65 consecutive patients diagnosed with re-TAIMH and treated by TEVAR were enrolled in this retrospective cohort study, of whom 44 patients presented with entry tear in descending aorta (Group A) and 21 with penetrating atherosclerotic ulcer (Group B). The clinical data, including baseline characteristics, adverse events, aortic remolding, and overall survival were reviewed.

Results: The mean age of all the patients was 52.0 ± 8.3 years, and 54 (83.1%) patients were men. The mean maximal ascending aortic diameter (MAAD) was 43.1 ± 5.4 mm, and the mean maximal ascending aortic hematoma thickness (MAAHT) was 9.6 ± 4.7 mm. TEVAR was performed under general anesthesia in 53 (81.5%) patients, while 12 (18.5%) patients were treated under local anesthesia. There were two deaths during hospitalization (one with rupture and another with multiple organ dysfunction syndrome), and overall survival at 1, 4, and 7 years for all 65 patients was 93.8, 92.0, and 87.4%, respectively. The MAAD and MAATH decreased significantly after TEVAR (p < 0.05) in the two groups, so did the mean descending aortic diameter at the pulmonary bifurcation level. Type I endoleak, dialysis, progression to type A aortic dissection, and enlargement in MAAHT and MAAD were more common complications, which occurred in four, three, two, and two patients, respectively.

Conclusion: Patients with retrograde TAIMH treated by TEVAR had a favorable prognosis including late survival and aortic remolding. However, some post-intervention complications were not negligible.